In recent years, the incidence of lifestyle-related diseases is increasing among Japanese people on account of changes in their eating habit and lifestyle. Lifestyle-related diseases is the generic term for diseases including not only hypertension, hyperlipidemia and diabetes but also other diseases, such as angina pectoris, myocardial infarction, cerebral circulatory disturbance and malignant tumors, which might be prevented from manifestation by improving lifestyle. Diseases such as hypertension, hyperlipidemia and diabetes often develop in combination and if one disease is complicated by another, the morbidity of the respective diseases changes for the worse and sequelae such as arteriosclerosis are caused at high incidence, leading to poor prognosis.
Recently, it has been found that one of the factors involved in such vicious circle is vascular endothelial hypofunction (see Non-Patent Document 1). Risk factors in vascular endothelial hypofunction include hypertension, impaired glucose tolerance, hyperlipidemia, postmenopausal women, smoking, etc. and discovering and preventing the vascular endothelial hypofunction as a precursor of a vascular lesion before it causes arteriosclerosis in the terminal state is considered to be of utmost importance for the purpose of preventing lifestyle-related disease. In particular, as regards a vascular lesion that is a chronic asymptomatic disease, prevention by foods that can be ingested safely for a prolonged time is considered to be more important and the development of foods that exhibit such beneficial effect is being expected.
It has also been shown that the higher the intake of polyphenols, the lower the incidence of diseases in circulatory organs and recent studies have reported that foods and food ingredients such as cocoa, chocolate, grapes and wine that are rich in procyanidins as major polyphenols are effective in improving the vascular endothelial function in humans (see Non-patent Documents 2 to 4). It has also been verified that oral administration of capsules containing a pine bark extract containing procyanidins is effective in improving the vascular endothelial function (see Non-patent Documents 5 and 6).    [Non-patent Document 1] Verma S, Anderson T J, Circulation 2002; 105:546-549    [Non-patent Document 2] Stein J H, Circulation 1999; 100:1050-5    [Non-patent Document 3] Chou E J, Am J Cardiol 2001; 88:553-5    [Non-patent Document 4] Agewall S, Eur Heart J 2000; 21:74-8    [Non-patent Document 5] Shand B, Phytother Res 2003; 17:490-4    [Non-patent Document 6] Young J M, Free Radic Res 2006; 40:85-94